We report dynamic holographic imaging with organic photorefractive polymer composites, doped with the electro-optic chromophore (2-(p-chlorophenyl)-(3′-nitrobenzo[d])-(4′′-methoxybenzo[h])-1,3-dioxa-6-aza-2-boracyclonon-6-ene, a push-pull molecule derived from a new class of boronates. The composites are based on the photoconductor poly(9-vinylcarbazole) (PVK) as the polymer matrix, and 9-ethylcarbazole (ECZ) as the plasticizer, with the fullerene C 60 as sensitizer. A tilted four-wave mixing geometry was used to record and reconstruct two-dimensional test objects, using a 10 mW He – Ne laser (632.8 nm). The recording response time was less than one second for a light intensity of ≈350 mW/cm 2 in each writing beam. The erasing time had a similar value. These composites have been used for over one year with no appreciable signs of degradation or crystallization.

Sodium salt heparins of both reactive and pharmaceutical grade were used as the reducing and stabilizing agents for the UV photochemical synthesis of gold nanoparticles. Reduction of chloroauric acid, HAuCl 4 , by heparin using UV irradiation as a catalyst is a simple, inexpensive method with direct biofunctionalization of the products for further use. Experiments using both heparin types were carried out separately. The varying synthesis parameters were the HAuCl 4 and heparin sodium concentrations. The synthesized AuNPs present spherical as well as anisotropic shapes, such as oval, triangular, hexagonal sheets, rods, and some other faceted forms, with dimensions ranging from 20 to 300 nm as well as agglomerated networks. No usage of additional surfactants or growth-inducing seeds was necessary in the syntheses.

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The preparation and characterization of organic photorefractive polymer composites derived from (2-(p-chlorophenyl)-(3'-nitrobenzo[d])-(4''-methoxybenzo[h])-1,3-dioxa-6-aza-2-boracyclonon-6-ene, a push-pull boronate, which shows NLO properties, are described. The polymers are based in the photoconductor poly(9-vinylcarbazole) and the plasticizer 9-ethylcarbazole PVK:ECZ matrix, and C 60 as sensitizer. For the photorefractive performance, two different chromophore concentrations were used, in addition, the ratio of PVK:ECZ was varied to see the effect on the room temperature molecular orientation. Holographic experiments in a tilted four and two wave mixing geometry were performed by using a 10 mW He-Ne laser (632.8 nm). The experiments were performed at room temperature, with a fixed grating spacing Λ of 2.9 µm, for determining the electric field steady-state diffraction efficiency dependency and the optical gain of the composites. Acceptable photorefractive properties were observed for a polymer with a glass transition temperature T g of 77 °C. Even at this T g , the response time was less than one second.

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